net: annotate data-races around sk->sk_tsflags

sk->sk_tsflags can be read locklessly, add corresponding annotations.

Fixes: b9f40e21 ("net-timestamp: move timestamp flags out of sk_flags")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -94,7 +94,7 @@ static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
 	ipcm_init(ipcm);
 
 	ipcm->sockc.mark = READ_ONCE(inet->sk.sk_mark);
-	ipcm->sockc.tsflags = inet->sk.sk_tsflags;
+	ipcm->sockc.tsflags = READ_ONCE(inet->sk.sk_tsflags);
 	ipcm->oif = READ_ONCE(inet->sk.sk_bound_dev_if);
 	ipcm->addr = inet->inet_saddr;
 	ipcm->protocol = inet->inet_num;

include/net/sock.h

@@ -1906,7 +1906,9 @@ struct sockcm_cookie {
 static inline void sockcm_init(struct sockcm_cookie *sockc,
 			       const struct sock *sk)
 {
-	*sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
+	*sockc = (struct sockcm_cookie) {
+		.tsflags = READ_ONCE(sk->sk_tsflags)
+	};
 }
 
 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
@@ -2701,9 +2703,9 @@ void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
 static inline void
 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
 {
-	ktime_t kt = skb->tstamp;
 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
-
+	u32 tsflags = READ_ONCE(sk->sk_tsflags);
+	ktime_t kt = skb->tstamp;
 	/*
 	 * generate control messages if
 	 * - receive time stamping in software requested
@@ -2711,10 +2713,10 @@ sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
 	 * - hardware time stamps available and wanted
 	 */
 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
-	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
-	    (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
+	    (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
+	    (kt && tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
 	    (hwtstamps->hwtstamp &&
-	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
+	     (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
 		__sock_recv_timestamp(msg, sk, skb);
 	else
 		sock_write_timestamp(sk, kt);
@@ -2736,7 +2738,8 @@ static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
 			   SOF_TIMESTAMPING_RAW_HARDWARE)
 
-	if (sk->sk_flags & FLAGS_RECV_CMSGS || sk->sk_tsflags & TSFLAGS_ANY)
+	if (sk->sk_flags & FLAGS_RECV_CMSGS ||
+	    READ_ONCE(sk->sk_tsflags) & TSFLAGS_ANY)
 		__sock_recv_cmsgs(msg, sk, skb);
 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
 		sock_write_timestamp(sk, skb->tstamp);

net/can/j1939/socket.c

@@ -974,6 +974,7 @@ static void __j1939_sk_errqueue(struct j1939_session *session, struct sock *sk,
 	struct sock_exterr_skb *serr;
 	struct sk_buff *skb;
 	char *state = "UNK";
+	u32 tsflags;
 	int err;
 
 	jsk = j1939_sk(sk);
@@ -981,13 +982,14 @@ static void __j1939_sk_errqueue(struct j1939_session *session, struct sock *sk,
 	if (!(jsk->state & J1939_SOCK_ERRQUEUE))
 		return;
 
+	tsflags = READ_ONCE(sk->sk_tsflags);
 	switch (type) {
 	case J1939_ERRQUEUE_TX_ACK:
-		if (!(sk->sk_tsflags & SOF_TIMESTAMPING_TX_ACK))
+		if (!(tsflags & SOF_TIMESTAMPING_TX_ACK))
 			return;
 		break;
 	case J1939_ERRQUEUE_TX_SCHED:
-		if (!(sk->sk_tsflags & SOF_TIMESTAMPING_TX_SCHED))
+		if (!(tsflags & SOF_TIMESTAMPING_TX_SCHED))
 			return;
 		break;
 	case J1939_ERRQUEUE_TX_ABORT:
@@ -997,7 +999,7 @@ static void __j1939_sk_errqueue(struct j1939_session *session, struct sock *sk,
 	case J1939_ERRQUEUE_RX_DPO:
 		fallthrough;
 	case J1939_ERRQUEUE_RX_ABORT:
-		if (!(sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE))
+		if (!(tsflags & SOF_TIMESTAMPING_RX_SOFTWARE))
 			return;
 		break;
 	default:
@@ -1054,7 +1056,7 @@ static void __j1939_sk_errqueue(struct j1939_session *session, struct sock *sk,
 	}
 
 	serr->opt_stats = true;
-	if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
+	if (tsflags & SOF_TIMESTAMPING_OPT_ID)
 		serr->ee.ee_data = session->tskey;
 
 	netdev_dbg(session->priv->ndev, "%s: 0x%p tskey: %i, state: %s\n",

net/core/skbuff.c

@@ -5207,7 +5207,7 @@ static void __skb_complete_tx_timestamp(struct sk_buff *skb,
 	serr->ee.ee_info = tstype;
 	serr->opt_stats = opt_stats;
 	serr->header.h4.iif = skb->dev ? skb->dev->ifindex : 0;
-	if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) {
+	if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID) {
 		serr->ee.ee_data = skb_shinfo(skb)->tskey;
 		if (sk_is_tcp(sk))
 			serr->ee.ee_data -= atomic_read(&sk->sk_tskey);
@@ -5263,21 +5263,23 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
 {
 	struct sk_buff *skb;
 	bool tsonly, opt_stats = false;
+	u32 tsflags;
 
 	if (!sk)
 		return;
 
-	if (!hwtstamps && !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TX_SWHW) &&
+	tsflags = READ_ONCE(sk->sk_tsflags);
+	if (!hwtstamps && !(tsflags & SOF_TIMESTAMPING_OPT_TX_SWHW) &&
 	    skb_shinfo(orig_skb)->tx_flags & SKBTX_IN_PROGRESS)
 		return;
 
-	tsonly = sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TSONLY;
+	tsonly = tsflags & SOF_TIMESTAMPING_OPT_TSONLY;
 	if (!skb_may_tx_timestamp(sk, tsonly))
 		return;
 
 	if (tsonly) {
 #ifdef CONFIG_INET
-		if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_STATS) &&
+		if ((tsflags & SOF_TIMESTAMPING_OPT_STATS) &&
 		    sk_is_tcp(sk)) {
 			skb = tcp_get_timestamping_opt_stats(sk, orig_skb,
 							     ack_skb);

net/core/sock.c

@@ -937,7 +937,7 @@ int sock_set_timestamping(struct sock *sk, int optname,
 			return ret;
 	}
 
-	sk->sk_tsflags = val;
+	WRITE_ONCE(sk->sk_tsflags, val);
 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
 
 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
@@ -1719,7 +1719,7 @@ int sk_getsockopt(struct sock *sk, int level, int optname,
 
 	case SO_TIMESTAMPING_OLD:
 		lv = sizeof(v.timestamping);
-		v.timestamping.flags = sk->sk_tsflags;
+		v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
 		v.timestamping.bind_phc = sk->sk_bind_phc;
 		break;
 

net/ipv4/ip_output.c

@@ -981,7 +981,7 @@ static int __ip_append_data(struct sock *sk,
 	paged = !!cork->gso_size;
 
 	if (cork->tx_flags & SKBTX_ANY_TSTAMP &&
-	    sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
+	    READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID)
 		tskey = atomic_inc_return(&sk->sk_tskey) - 1;
 
 	hh_len = LL_RESERVED_SPACE(rt->dst.dev);

net/ipv4/ip_sockglue.c

@@ -511,7 +511,7 @@ static bool ipv4_datagram_support_cmsg(const struct sock *sk,
 	 * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
 	 */
 	info = PKTINFO_SKB_CB(skb);
-	if (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG) ||
+	if (!(READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_CMSG) ||
 	    !info->ipi_ifindex)
 		return false;
 

net/ipv4/tcp.c

@@ -2259,14 +2259,14 @@ void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
 			}
 		}
 
-		if (sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE)
+		if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_SOFTWARE)
 			has_timestamping = true;
 		else
 			tss->ts[0] = (struct timespec64) {0};
 	}
 
 	if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) {
-		if (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)
+		if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_RAW_HARDWARE)
 			has_timestamping = true;
 		else
 			tss->ts[2] = (struct timespec64) {0};

net/ipv6/ip6_output.c

@@ -1501,7 +1501,7 @@ static int __ip6_append_data(struct sock *sk,
 	orig_mtu = mtu;
 
 	if (cork->tx_flags & SKBTX_ANY_TSTAMP &&
-	    sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
+	    READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID)
 		tskey = atomic_inc_return(&sk->sk_tskey) - 1;
 
 	hh_len = LL_RESERVED_SPACE(rt->dst.dev);

net/ipv6/ping.c

@@ -119,7 +119,7 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 		return -EINVAL;
 
 	ipcm6_init_sk(&ipc6, np);
-	ipc6.sockc.tsflags = sk->sk_tsflags;
+	ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags);
 	ipc6.sockc.mark = READ_ONCE(sk->sk_mark);
 
 	fl6.flowi6_oif = oif;

net/ipv6/raw.c

@@ -772,7 +772,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	fl6.flowi6_uid = sk->sk_uid;
 
 	ipcm6_init(&ipc6);
-	ipc6.sockc.tsflags = sk->sk_tsflags;
+	ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags);
 	ipc6.sockc.mark = fl6.flowi6_mark;
 
 	if (sin6) {

net/ipv6/udp.c

@@ -1339,7 +1339,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
 	ipcm6_init(&ipc6);
 	ipc6.gso_size = READ_ONCE(up->gso_size);
-	ipc6.sockc.tsflags = sk->sk_tsflags;
+	ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags);
 	ipc6.sockc.mark = READ_ONCE(sk->sk_mark);
 
 	/* destination address check */

net/socket.c

@@ -825,7 +825,7 @@ static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp)
 
 static ktime_t get_timestamp(struct sock *sk, struct sk_buff *skb, int *if_index)
 {
-	bool cycles = sk->sk_tsflags & SOF_TIMESTAMPING_BIND_PHC;
+	bool cycles = READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_BIND_PHC;
 	struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 	struct net_device *orig_dev;
 	ktime_t hwtstamp;
@@ -877,12 +877,12 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
 	int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
 	int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
 	struct scm_timestamping_internal tss;
-
 	int empty = 1, false_tstamp = 0;
 	struct skb_shared_hwtstamps *shhwtstamps =
 		skb_hwtstamps(skb);
 	int if_index;
 	ktime_t hwtstamp;
+	u32 tsflags;
 
 	/* Race occurred between timestamp enabling and packet
 	   receiving.  Fill in the current time for now. */
@@ -924,11 +924,12 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
 	}
 
 	memset(&tss, 0, sizeof(tss));
-	if ((sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) &&
+	tsflags = READ_ONCE(sk->sk_tsflags);
+	if ((tsflags & SOF_TIMESTAMPING_SOFTWARE) &&
 	    ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0))
 		empty = 0;
 	if (shhwtstamps &&
-	    (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
+	    (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
 	    !skb_is_swtx_tstamp(skb, false_tstamp)) {
 		if_index = 0;
 		if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV)
@@ -936,14 +937,14 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
 		else
 			hwtstamp = shhwtstamps->hwtstamp;
 
-		if (sk->sk_tsflags & SOF_TIMESTAMPING_BIND_PHC)
+		if (tsflags & SOF_TIMESTAMPING_BIND_PHC)
 			hwtstamp = ptp_convert_timestamp(&hwtstamp,
 							 sk->sk_bind_phc);
 
 		if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) {
 			empty = 0;
 
-			if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&
+			if ((tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&
 			    !skb_is_err_queue(skb))
 				put_ts_pktinfo(msg, skb, if_index);
 		}